https://bugs.winehq.org/show_bug.cgi?id=56087
--- Comment #11 from Cedric cedric.dewijs@eclipso.eu --- (In reply to Rafał Mużyło from comment #10)
...yet the early warnings make me wonder: is wine-mono properly installed in the prefix ?
I started with an empty prefix, where by definition wine-mono was not installed. Wine-mono has been installed system-wide: $ pacman -Q wine-mono wine-mono 8.1.0-1